Improvement in self-closing hatchways



A. e. STEVENS.

SELF-CLOSING HATC HWAYS'. lat'e'nte'd Nov. 21, 1876.

THE GRAPHIC CO. N.\

'Sheets-Sheet 2.

UNITED STATES PATENT OEEIoE.

AUGUSTUS e. STEVENS, OF MANCHESTER, NEw HAMPSHIRE.

IMPROVEMENT IN SELF-CLOSING HATCHWAYS.

Specification forming part of Letters Patent No. 184 ,671, datedNovember 21, 1876; application filed May 15, 1876.

To all whom it may concern I Be it known that I, AUGUSTUS G. STEVENS, ofManchester, in the county of Hillsborough and State of New Hampshire,have invented certain new and useful Improvements in Elevators, of whichthe following-is a specification that will enable those skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, which form part of this specification.

My invention consists in the features and combinations hereinafterdescribed, and more particularly specified in my claims.

In the drawings I have represented the frame of an elevator inminiature, with my invention applied.

Figure 1 is an elevation, and Figs. 2, 3, and 4 are detail views. Y

The frame, for purposes of illustration, is represented as resting uponthe base A, which corresponds to the lower floor of a building providedwith my elevator. B represents the second floor, and O O the postsconnected at their tops. Upon these posts are the double racks D D,having their teeth or cogs inclined for engagement with the spiral orworm gears of the elevator. E represents the car or platform.. On thisplatform rest the two inclined bearings FF, carryinginclined shaftsgeared together at their inner ends by the two beveled gears G G. Nearthe outer ends of these shafts, which project into the spaces betweenthe racks, and keep the platform in place, are the scrolls or worm gearsH E, that engage with the double racks D D for raising and lowering theelevator. Motion is communicated to the inclined shafts and worm gearsby means of the grooved pulley I, cord or cable J, grooved pulleys K K,and grooved weight-sheave L, which last must be sufficiently heavy togive proper tension and friction to the cord or cable. The pulleys K Kare loose on the same or different shafts, and always revolved inopposite directions. When the pulley K is turned in the direction of thearrow the elevator will be raised, and the weight-sheave willcorrespondingly descend. If turned in the opposite direction theelevator will descend and the weightsheave will rise.

. ment of pulleys a flat band could be used in- 7 stead of a cord.Should the cord break the elevator could not fall, because it would beheld by the scrolls (the revolution of which would cease) engaging withthe racks. Breaks could be applied to the pulleys as additionalsecurity, but in practice it will be, found that they are not necessary,and that the scrolls will insure perfect safety.

To close the opening on each floor as soon as the elevator has passedabove or below it, in order to prevent accidents from falling, and toprevent the spread of fire through the several stories of a building, Ihave provided automatic hatches or trap-doors M M, hinged to the cornersof the openings. To the outer sides of these doors, near the posts 0 O,are attached the segmental gears N N, which engage with the pivotedswinging rack-levers O 0. To the lower ends of these levers are attachedthe shoes or strikers P P. As the elevator rises and approaches a floorabove it the curved lifters or cams Q Q strike the shoes, swing thepivoted levers outward, and cause the trap-doors to swing upward ontheir hinges, and rest in perpendicular position against the posts 0 Oin a space cut away for the purpose. On the under sides of the doors aresections of racks d d, which, when the doors are opened and inperpendicular position against the posts, coincide with and form acontinuation of the racks on the posts whereby the elevator ascendswithout interruption. the rack supplied by the platform the trapdoorsimmediately fall by their own weight to close the aperture, beingpivoted and geared to the swinging levers, so as to insure this actionby the force of gravity; but to prevent them from closing too suddenly,and producing a shock, the rack-levers are provided with curvedprojections o 0 on their inner faces, which press against the contiguousedges of the platform or elevator as it ascends, caus-- ing the doors tofall slowly and noiselessly. When in descending the elevator approachesa floor below it these curved projections are struck and pressedoutward, which, as will be apparent from the drawings, will cause thetrap-doors to be opened and set in perpen- When it has passed thesections of v dicular position to form a continuation of tbe rack, andpermit the uninterrupted. passage of the elevator on its descent, asabove set forth respecting its ascent. When it passes down below a givenfloor the trapdoors immediately tend toclose above it by gravity, butare prevented from slamming by the engagement of the shoes P P with thelifters or cams Q Q. are thus operated automatically, and theirmovements, both in opening and closing, are it under positive control ofthe elevating mechanism.

When desirable, I propose to have a single transverse shaft for theworm-gears, as shown in Fig. 4.

My invention insures absolute safety from the accidents so commonlyincident to elevators.

What I claim as new, and desire to secure by Letters Patent, is-

1. The combination of the inclinedbearings F F, the shafts projectinginto the spaces between the racks, the scrolls or worm-gears H H, andthedouble racks with inclined teeth, substantially as and for the purposesspecified.

The trap-doors or hatches.

2. The combination of the pivoted rack-levers, the shoes or; strikers, PP", and thelift ers or cams Q Q( forcontrolling the movementsof thehatches when the elevator is begears and projecting at each end into theguide spaces of the racks, all constructed and operating substantiallyas and for the purposes set forth.

In testimony whereofl. have hereunto subscribed my name.

. AUGUSTUS STEVENS.

Witnesses:

RICHARD J. P. Goonwm, Mrs. BETSEY. J Hon.

